Damor Pradipkumar R, Sharma Sidhartha, Kumar Vijay, Chawla Amrita, Logani Ajay
Division of Conservative Dentistry and Endodontics, Centre for Dental Education and Research, All India Institute of Medical Sciences, New Delhi, India.
J Conserv Dent Endod. 2024 Apr;27(4):424-428. doi: 10.4103/JCDE.JCDE_77_24. Epub 2024 Apr 5.
Dentinal microcracks formed during apical resection may lead to increased susceptibility to root fracture and improper sealing of apical preparation that may negatively influence the outcome of endodontic microsurgery.
This study was performed to analyze the root-end surface for dentinal microcracks using a scanning electron microscope (SEM) after resection with high-speed bur and trephine drill.
Thirty extracted single-rooted maxillary premolar teeth were selected and randomly distributed into two groups ( = 15). Working length was established using a #15 K-type file. Canals were prepared with a rotary Ni-Ti system to size 30/0.06 using endomotor, irrigated with 3% sodium hypochlorite, dried with paper points, and obturated with gutta-percha cones using a single-cone technique. All samples were mounted on preformed molds and poured using a mixture of sawdust and gypsum. In Group A; tungsten carbide bur was used to perform a freehand apicoectomy. In Group B; a trephine drill was used with a three-dimensional guide to perform 3 mm of root resection. Apicoectomy was performed in both groups under a dental operating microscope. Resected root ends were inspected for microcracks using SEM. The Shapiro-Wilk and Mann-Whitney U-test were used for statistical analysis.
Microcracks were observed in all samples in both study groups. Trephine drill produced more microcracks on the resected root surface compared to the use of high-speed tungsten carbide bur with a statistically significant difference ( < 0.05).
The trephine drill used during targeted endodontic microsurgery produced more microcracks on the resected root dentine surface compared to the high-speed tungsten carbide bur used during freehand apicoectomy.
根尖切除术过程中形成的牙本质微裂纹可能会导致牙根骨折的易感性增加，以及根尖预备的密封不当，这可能会对牙髓显微手术的结果产生负面影响。
本研究旨在使用高速牙钻和环钻切除后，通过扫描电子显微镜（SEM）分析根尖表面的牙本质微裂纹。
选取30颗拔除的单根上颌前磨牙，随机分为两组（每组n = 15）。使用15号K型锉确定工作长度。采用旋转镍钛系统将根管预备至30/0.06号，使用根管马达，用3%次氯酸钠冲洗，用纸尖干燥，采用单尖技术用牙胶尖充填。所有样本均安装在预制模具上，并用锯末和石膏的混合物灌注。A组使用碳化钨牙钻进行徒手根尖切除术。B组使用带有三维导向的环钻进行3mm的牙根切除术。两组均在牙科手术显微镜下进行根尖切除术。使用扫描电子显微镜检查切除的根尖表面是否有微裂纹。采用Shapiro-Wilk检验和Mann-Whitney U检验进行统计分析。
两个研究组的所有样本中均观察到微裂纹。与使用高速碳化钨牙钻相比，环钻在切除的牙根表面产生了更多的微裂纹，差异具有统计学意义（P < 0.05）。
与徒手根尖切除术中使用的高速碳化钨牙钻相比，靶向牙髓显微手术中使用的环钻在切除的牙根牙本质表面产生了更多的微裂纹。
